oxygen sensor
#28
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Question about the shielding, i bought a 02 sensor from rx7.com which came with a different connector than my car has (S5 n/a) they told me it was OK to splice the connector onto the O2 sensor and just connect it into the plug in the engine bay. If its shielded, then such a splice would be bad? correct? (Its been like that for a year, and no engine light has come on.)
#29
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well today i grounded the **** out of the motor, and hooked the 02 sensor up, by splicing into the wire, still get nothing and at wot i get one red lean led, So i go out and cut the wire to the ecu and i start getting leds, its showing idle just fine. Then i take it out for a drive, adn the lights go off except under wot what the hell is going on???? Please help
#30
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SUNSHINE....Don't worry about the lack of the shielded wire. The shield is not completly from end to end. It ends about six to eight inches from the ECU and ends prior to the termination of the end that is at the 02 sensor. As long as you don't(and you didn't) accidently do your splice or crimp where the shield touches the center conductor, there's no problem. My 87 N/A has about three feet not shielded and I get normal milage when driving on long trips (26 on hwy on 900 mile trips) and no 02 codes.
#32
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I also have my a/f meter hooked up to the wire comming off the o2 sensor and it seems to work fine.....how can you tell if its running a closed loop?
#33
Originally posted by BlackRx7
I also have my a/f meter hooked up to the wire comming off the o2 sensor and it seems to work fine.....how can you tell if its running a closed loop?
I also have my a/f meter hooked up to the wire comming off the o2 sensor and it seems to work fine.....how can you tell if its running a closed loop?
#34
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well to bring an older thread back to life. I recently went out and bought the 37 dollar o2 sensor that belongs on my car to replace the universal sensor that was on there causing my probs. [i thought] And what do you know it did nothing different. same old ****. I have not had a chance to hook it up to a scanner yet. But will here soon i hope, {where can i purchase one of these?}
yes i know they are expensive, but who has them. Also I did not ground it yet, but would this really make a big difference??? i mean, the hole downpipe, and exhaust should be grounded from the motor anyways RIGHT??
WEll i don't know, I really need help here.
Or could my car just be running that lean? when you start it cold, it shows rich, and as it begins to warm, it starts moving towards stoich, but after you drive for a minute when it starts getting warm the leds just go away, at a light cruise.. when you let off the gas it all of a sudden bounces from lean to rich, then dies out. no leds. and not at wot, but on the gas, the leds come on and you get a stoich-rich reading? and at wot you get a rich. but at idle you don't get ****?
PLease help me!!!!!!!!!
yes i know they are expensive, but who has them. Also I did not ground it yet, but would this really make a big difference??? i mean, the hole downpipe, and exhaust should be grounded from the motor anyways RIGHT??
WEll i don't know, I really need help here.
Or could my car just be running that lean? when you start it cold, it shows rich, and as it begins to warm, it starts moving towards stoich, but after you drive for a minute when it starts getting warm the leds just go away, at a light cruise.. when you let off the gas it all of a sudden bounces from lean to rich, then dies out. no leds. and not at wot, but on the gas, the leds come on and you get a stoich-rich reading? and at wot you get a rich. but at idle you don't get ****?
PLease help me!!!!!!!!!
#36
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I don't have a meter like you all, but I occasionally monitor my o2 with a digital meter. At idle the reading is a minus voltage since the air pump is pumping fresh air directly into the exaust ports.. When driving, and you let off the gas, the voltage drops into the minus anytime you let off the throttle just a tad. Thats normal since the ECU is cutting the mixture the moment you let off the throttle. Heavy on the throttle I get approx .8 volts. If I'm cruising in fifth at say sixty or seventy, the volt meter will be constantly jumping on either side of approx .4volts. It does this rapidly, say .2 to .5 to .1 to .7 to .3 to .5 etc. Thats just an example. In other words if crusing, the lights should be jumping around stoic or approx .4. There is a better explanation on the Autometer.com site under the faq there on that site. If my emissions is not working as designed, and the relief and switching solenoids are not working, I will read .6 or .7 at idle. Thats due to no airpump air being injected into the exaust ports. Seeing that figure at idle alerts me that something is amiss with my emissions system.
#38
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If you do not have an air pump, the 02 should read in the .6 to .7 range. I'd find someone with a DIGITAL volt meter and set it on the lowest dc voltage scale and put the neg lead on a good ground and the positive lead on the connector wire where the 02 sensor meets the car harness. Start the car. After some warming up it should read .6 plus at idle with no air pump. Acv is irrelevant in your case. OR. Send me the o2 sensor and gauge and I'll put it on my car and see what happens. You pay the postage both ways.
#39
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so, why would the air pump matter, but the acv vavle not. this is where the air is pumped to from the airpump right? Well, i have this pluged up, so, why would that not make a difference? Oh, and it sounds tempting to mail it to ya. Would a cheap digital volt meter, like from radio shak work?
#40
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YES! A cheap twenty dollar one is just fine. Only poblem with those is the leads are a touch short, but you can work around that. The acv is fed by the airpump. No air pump, the acv is mostly useless. It has diaphrams that open and shut and shuttle air from the air pump to the exaust ports and the split air pipe that runs to the catalytic converter. Also shoots fresh air into the intake under rapid deceleration to prevent backfire etc. So without the airpump its opening and shutting poppet valves internal to it, but theres no air to shuttle around. You really should send the whole unit to me. Trust me. I've been out of Huntsville Unit for several years now and am fully rehabilitated. It was a minor crime of mail fraud. Trust me. Lets see if I'm really rehabilitated. Yeah the cheaper digital meters don't have long leads. Ask the fellow at the Radio Shack how he thinks you can work around this. Maybe alligator clips and a spool of 18 gauge wire to supplement the length. And if you can't connect with the Huntsville Unit.......think barbwire fences, electric chairs, bars on cells etc. But trust me, send me the unit and I'll take care of it.
#41
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Well see here in the next day or so. also, would this even make any sense, i do not have the o2 hooked up to the ecu, so its just the guage and the sensor. the guage is directly hooked up to the batt and the sensor, nothing else. and this is the second sensor. so Could the guage be bad, i do get some lights some time....
Or do you think its just that lean of a setting? I don't think that mailing them to you would really help me much.
Or do you think its just that lean of a setting? I don't think that mailing them to you would really help me much.
#42
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I plead ignorance. I've never disconnected the 02 from the ECU and observed the 02 sensor reading. It certainly won't be hunting on both sides of stoic since the ECU will be in open loop*see Autometer.com for how 02 sensors and meters work*. Should definitly read approx .6 to .7 at idle and .7 to .8 at full throttle. Wellllll it might not help you if you send the meter and senor to me, but it will help JOE'S PAWN SHOP's inventory. Mazda never made a RX7 that ran that lean. Just ain't possible . I still think the meter*digital* is the way to go to find out if the sensor or the gauge is bad.
#45
Dont know what you mean by "cheap", but you should set it to the lowest "DC" setting it has, touch the black connector to a good ground on your car or the chassis itself, and the red connector to the signal wire from the O2 sensor. You should see the voltages described above dancing in the LCD screen....
![Wink](https://www.rx7club.com/images/smilies/wink.gif)
#46
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cheap, like 20 bucks, it doesn't say dc on it anywhere, just a lot of little symbols. and i did connect it to the signal wire with it disconected from the ecu. and i got .03, this is on the same setting that showed my batt was at 14.0????????????????
#47
Originally posted by chris-reed
cheap, like 20 bucks, it doesn't say dc on it anywhere, just a lot of little symbols. and i did connect it to the signal wire with it disconected from the ecu. and i got .03, this is on the same setting that showed my batt was at 14.0????????????????
cheap, like 20 bucks, it doesn't say dc on it anywhere, just a lot of little symbols. and i did connect it to the signal wire with it disconected from the ecu. and i got .03, this is on the same setting that showed my batt was at 14.0????????????????
The meter seems to be working, so you should try and check the O2 more extensively...I would suggest connecting the meter to the ECU, and going for a -slow- ride on a back road. Try to see what voltages does the O2 sensor throws at you while cruising at various levels of throttle....
If the ECU hasnt thrown any error codes for the O2, I would suggest that the sensor is working fine, but rather you cannt get a good fix on the signal...
#48
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The symbols might be something like a straight line and under that straight line a dotted line. That should be DC volts. The symbol that is just a wavy line should be AC volts.
_________
--------- is DC volts
~ is AC volts
ohms is the upside down horseshoe
That meter should be more than good enough for what you do on this car.
I'm assuming that the above symbols are the ones you refer to. Can't figure what other symbols would be used. I'm your basic knuckle dragger.
_________
--------- is DC volts
~ is AC volts
ohms is the upside down horseshoe
That meter should be more than good enough for what you do on this car.
I'm assuming that the above symbols are the ones you refer to. Can't figure what other symbols would be used. I'm your basic knuckle dragger.
Last edited by HAILERS; 05-28-02 at 08:20 AM.
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